1. Field of the Invention
The invention relates to generally to intra-uterine devices, including hysteroscopes and related devices for microsurgical use such as use in the field of embryo implantation.
2. Description of the Related Arts
Improving the success of in vitro fertilization (IVF) depends on many factors, one of which is the delivery or transfer of the embryo to the endometrial lining of the uterus and the successful implantation of the embryo therein. It is well known in the art that assisting an embryo to adhere to, or implant within, a pre-determined area of the endometrial lining of the uterine wall, as opposed to simply releasing the embryo into the uterus, will enhance the success of IVF, minimize the risk of tubal pregnancies and reduce high-order multiple births.
U.S. patent application Ser. No. 09/759,415, filed Jan. 12, 2001, titled “Method and Apparatus for Assisted Embryo Implantation,” describes a minimally invasive embryo transfer method, which, in one embodiment, describes a specially formed microcatheter to gently deliver one or more selected embryos into a pocket formed within the endometrial lining of a subject's uterus.
A microcatheter, such as described for use in the referenced document, is inserted typically by way of a hysteroscope. A hysteroscope is generally a specialized endoscopic device, for intrauterine use, which provides for direct or video observation of the interior of a subject's uterus and provides a platform for microsurgical instruments such as catheters by providing a channel or lumen through the device. Representative endoscopes are described in U.S. Pat. No. 6,006,002 issued to Motoki, et al.; U.S. Pat. No. 4,534,339 issued to Collins, et al.; and U.S. Pat. No. 4,203,430 issued to Takahashi. To enhance the field of vision of a hysteroscope within the uterus, often the uterus will be insufflated with a gas to distend the uterine walls. In addition to providing a channel or lumen through the device for instruments, prior art hysteroscopes may provide an additional channel or lumen for a gas introduction. A hysteroscopic device for performing a minimally invasive microsurgical intrauterine procedure such as an embryo implantation procedure should be small enough so that the subject's uterus may be accessed comfortably without inducing dilation. Multiple lumen devices tend to cause discomfort and are generally difficult to maneuver. What is needed is an improved endoscopic device that may provide a stable platform for use of such a microcatheter or other instrument.